JP4422991B2 - Developing device, process cartridge, and electrophotographic image forming apparatus - Google Patents

Description

  The present invention relates to a developing device, a process cartridge, and an electrophotographic image forming apparatus.

  2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus, an electrophotographic photosensitive drum (hereinafter referred to as “photosensitive drum”) and process means acting on the photosensitive drum are integrally formed into a cartridge, and this cartridge is used as an image forming apparatus. A process cartridge system that is detachable from the main body is employed. According to this process cartridge system, the maintenance of the apparatus can be performed by the operator himself / herself without depending on the service person, so that the operability can be remarkably improved. For this reason, this process cartridge system is widely used in electrophotographic image forming apparatuses.

  In such a process cartridge, a photosensitive drum is provided, and a developing unit is used to apply a developer (toner) to a latent image formed on the photosensitive drum.

  The developing means includes a developing container frame that holds a developing sleeve that supplies toner to the photosensitive drum, and a toner container that stores toner provided in combination with the developing container frame. Note that the opening provided in the developing container frame is hermetically sealed with a toner seal member before use.

  In Patent Document 1, when a process cartridge is mounted on the electrophotographic image forming apparatus main body, a toner seal member that seals the opening is wound by a winding member to which one end of the toner seal member is fixed. A configuration for automatically opening the opening has been proposed.

  Patent Document 1 also describes a stirring member as a rotating member that stirs the toner in the toner storage container.

  Patent Document 2 proposes a configuration using an elastic sheet member that rotates around a stirring shaft as a developer stirring device.

  Patent Document 3 proposes a configuration in which the developer stirring member is constituted by divided blade portions. And between the said blade | wing parts, the screw structure part which transmits a rotational driving force with a time difference is provided.

  However, when the take-up shaft of the toner seal member and the stirring member are rotated by one drive source provided in the electrophotographic image forming apparatus main body, it is necessary to select the drive source in consideration of the following torque. It was.

  Specifically, the first is the load torque generated when the winding member is rotated to peel the toner seal member from the opening, and the second is the load torque generated when the agitating member is rotated. In particular, it is necessary to select a driving source in consideration of the maximum load torque generated when the stirring member is rotated in a state where the opening of the developer container is sealed with the toner seal member.

Therefore, there is provided drive means capable of generating a torque obtained by adding a load torque generated when rotating the winding member to a maximum load torque generated when rotating the stirring member in a state of being sealed by the toner seal member. It is necessary to make a selection, which leads to an increase in the size and cost of the apparatus.
Japanese Patent Laid-Open No. 2001-305839 (FIGS. 1 and 5) Japanese Patent Laid-Open No. 2001-075343 (FIG. 7) JP-A-6-348126 (FIG. 1)

  The present invention has been further developed in view of the above prior art.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a developing device and a process cartridge capable of reducing a driving torque necessary for driving a developer seal opening device and a stirring member.

In order to achieve the above object, the invention according to the present application
A developing device detachable from the electrophotographic image forming apparatus main body,
A developing roller that develops the electrostatic latent image formed on the electrophotographic photosensitive drum with a developer, and that is rotated by a driving force from a motor provided in the apparatus main body. A developing roller having a first gear provided at the end and a second gear provided at the other end in the longitudinal direction;
A developer storage container for storing the developer;
A stirring member provided in the developer storage container, the stirring member stirring the developer and supplying the developer to the developing roller;
An opening provided in the developer container for supplying the developer to the developing roller;
A developer seal member for sealing the opening;
A developer seal unsealing device having a take-up shaft for winding the developer seal member to open the developer seal member, to which a driving force is transmitted via the second gear;
A driving force transmission mechanism that transmits a driving force to the stirring member via the first gear, the first driving having a first screw portion that transmits the driving force from the first gear. A force transmission member, and a second driving force transmission member connected to the stirring member, the second driving force transmission member having a second screw portion meshed with the first screw portion, and the first driving force transmission member After the driving force is transmitted and the first screw part is rotated by a predetermined amount and fastened to the second screw, the second driving force transmitting member rotates to switch the rotation direction of the motor. And a driving force transmission mechanism that transmits a driving force to the stirring member after a predetermined time has elapsed since the winding shaft began to rotate,
It is characterized by having.

The invention according to the present application is
In a process cartridge that can be attached to and detached from the electrophotographic image forming apparatus main body,
The developing device;
An electrophotographic photosensitive drum;
It is characterized by having.

The invention according to the present application is
In an electrophotographic image forming apparatus for forming an image on a record medium,
(I) the process cartridge;
(Ii) transfer means for transferring a developer image formed on the electrophotographic photosensitive drum of the process cartridge to the recording medium;
(Iii) transport means for transporting the recording medium;
It is characterized by having.

As described above, according to the present invention, the stirring member starts to rotate later than the timing at which the pulling force generated when the developer seal member is peeled off reaches a peak. Therefore, the maximum driving torque required to drive the stirring member and the developer seal opening device can be reduced, which contributes to miniaturization and cost reduction of the motor .

  The best mode for carrying out the present invention will be exemplarily described in detail below with reference to the drawings and embodiments. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. . Further, the materials, shapes, etc. of the members once described in the following description are the same as those in the first description unless otherwise described.

  (Description of the entire electrophotographic image forming apparatus)

  Hereinafter, a developing device, a process cartridge, and an electrophotographic image forming apparatus according to the present embodiment will be described with reference to the drawings.

  First, an electrophotographic image forming apparatus in which a process cartridge according to this embodiment is detachably mounted will be described with reference to FIGS. FIG. 1 is a schematic cross-sectional view showing a configuration of an electrophotographic image forming apparatus A according to the present embodiment. FIG. 2 is a schematic cross-sectional view of a process cartridge B that can be attached to and detached from the electrophotographic image forming apparatus A according to this embodiment.

  Here, the electrophotographic image forming apparatus is an apparatus that forms an image on a recording medium such as recording paper, an OHP sheet, or cloth using an electrophotographic image forming system. For example, an electrophotographic copying machine, an electrophotographic printer (for example, an LED printer, a laser beam printer, etc.), an electrophotographic facsimile apparatus, an electrophotographic word processor, and the like are included. In this embodiment, a laser beam printer will be described as an example.

  The process cartridge refers to a cartridge in which at least the developing means as the process means and the electrophotographic photosensitive drum are integrally formed into a cartridge that can be attached to and detached from the main body of the electrophotographic image forming apparatus. The process means includes a charging means and a cleaning means.

  An electrophotographic image forming apparatus (laser beam printer) A (hereinafter referred to as image forming apparatus A) detachably mounts a process cartridge B described later.

  The image forming apparatus A conveys the recording medium 2 set in the cassette 3a to the transfer position by the pickup roller 3b and the conveying roller pairs 3c, 3d, and 3e in synchronization with the formation of the developer (toner) image in the cartridge B. To do.

  The developer image is transferred to the recording medium 2 by applying a voltage to a transfer roller (transfer means) 4 disposed at the transfer position.

  Thereafter, the recording medium 2 is transported to the fixing unit 5 through the transport guide 3f. The fixing unit 5 includes a driving roller 5c and a fixing roller 5b incorporating a heater 5a. The fixing unit 5 applies heat and pressure to the passing recording medium 2 to fix the developer image on the recording medium 2.

  The recording medium 2 is conveyed by the discharge roller pairs 3g and 3h, and is discharged to the discharge tray 6 via the reverse path 3i. The discharge tray 6 is provided on the upper surface of the image forming apparatus A. The swingable flapper 3j can be operated to discharge the recording medium 2 without going through the reversing path 3i. The pickup roller 3b, the conveyance roller pairs 3c, 3d, and 3e, the conveyance guide 3f, the discharge roller pairs 3g and 3h, and the like constitute the conveyance means 3 for the recording medium 2.

  The image forming apparatus main body A has a motor 23 as a drive source for driving the cartridge B. The driving force generated by the motor 23 is transmitted to the cartridge B via a gear 24 that is coaxial with the rotation shaft of the photosensitive drum 7 (FIG. 2).

  Next, the cartridge B according to the present embodiment will be described.

  The cartridge B includes a developing device 19 and a photoreceptor unit 20.

  The photosensitive unit 20 includes a drum-shaped electrophotographic photosensitive drum (hereinafter referred to as a photosensitive drum) 7, a charging roller 8 as a charging unit, and an elastic cleaning blade 17a. Here, the photosensitive drum 7, the charging roller 8, and the elastic cleaning blade 17 a are attached to the drum frame 18.

  The photosensitive drum 7 is charged by a charging roller 8 as charging means. Next, the photosensitive drum 7 is irradiated with laser beam light corresponding to image information from the optical means 1 having a laser diode, a polygon mirror, a lens, and a reflection mirror (not shown). Thereby, an electrostatic latent image corresponding to the image information is formed. This electrostatic latent image is developed with a developer (toner) by the developing device 19 to be a visible image, that is, a developer image (toner image).

  The cleaning unit 17 scrapes off the developer remaining on the photosensitive drum 7 after the developer image is transferred to the recording medium 2 by the transfer roller 4 and the residual toner on the photosensitive drum 7 by the elastic cleaning blade 17a. . Then, the toner is collected in a waste toner reservoir 17b.

  The developing device 19 includes a developer storage container (hereinafter referred to as a toner storage container) 14 that stores a developer, and a developing frame 13 that holds the developing roller 10 and the developing blade 12. The toner container 14 and the developing frame 13 are integrally coupled by means such as welding of flange portions 14b and 13b provided on the outer periphery of the toner container 14 and the developing frame 13.

  Further, the developing device 19 sends the developer in the toner container 14 to the developing chamber 13 a by the rotation of the stirring member 55. Then, the developing roller 10 including the magnet roller (fixed magnet) 11 is rotated, and a toner layer to which a frictional charge is applied by the developing blade 12 is formed on the surface of the developing roller 10. Then, the developer is transferred to the photosensitive drum 7 in accordance with the latent image, thereby forming a developer image to make a visible image.

  The developing blade 12 defines the amount of toner on the peripheral surface of the developing roller 10 and applies a triboelectric charge.

  (Configuration of frame of cartridge B)

  The structure of the frame of the cartridge B according to the present embodiment will be described with reference to FIG. FIG. 8 is an exploded perspective view of the process cartridge according to the present embodiment.

  As shown in FIG. 8, in the cartridge B, the developing device 19 and the photosensitive unit 20 are coupled to each other by a coupling member 31 of a round pin so as to be rotatable.

  Round ends 13d and 13e parallel to the developing roller 10 are provided at the ends of the arm portions 13b and 13c formed on both sides in the longitudinal direction of the developing frame 13 (axial direction of the developing roller 10).

  Concave portions 18a and 18b for allowing the arm portions 13b and 13c to enter are provided at two positions on both sides of the drum frame 18 in the longitudinal direction. And the arm parts 13b and 13c are inserted in the recessed parts 18a and 18b. After that, the coupling member 31 is inserted into the mounting holes 18c and 18d of the drum frame 18 and is fitted into the rotation holes 13d and 13e of the arm portions 13b and 13c, and further, a hole inside the drum frame 18 (not shown). Press fit into and attach. As a result, the photosensitive unit 20 and the developing device 19 are coupled so as to be rotatable about the coupling member 31. At this time, the compression coil springs 21 and 22 attached to the bases of the arm portions 13 b and 13 c hit the upper walls of the recesses 18 a and 18 b of the drum frame 18 and urge the developing device 19 downward. Thereby, the developing roller 10 is surely pressed against the photosensitive drum 7.

  (Installation of cartridge in the electrophotographic image forming apparatus)

  A method for mounting the process cartridge according to this embodiment to the image forming apparatus main body will be described with reference to FIGS. FIG. 3 is a perspective view illustrating a state in which the process cartridge is mounted on the image forming apparatus main body according to the present exemplary embodiment. 4 and 5 are perspective views showing the mounting means of the image forming apparatus main body according to the present embodiment. 6 and 7 are external perspective views of the process cartridge according to the present embodiment.

  As shown in FIG. 3, the cartridge B is detachably mounted on the cartridge mounting means provided in the image forming apparatus main body A by the operator by opening the cartridge door 9 of the image forming apparatus main body A.

  As shown in FIGS. 4 and 5, the cartridge mounting unit according to the present embodiment includes guide portions 30L1, 30L2, 30R1, and 30R2 formed on the image forming apparatus main body A. When the cartridge B is mounted on the image forming apparatus main body A, the cylindrical portions 40R1, 40R2, 40L1, and 40L2 (see FIGS. 6 and 7) provided on both outer surfaces of the cartridge B are respectively guided to the image forming apparatus main body. Insert along the sections 30R1, 30R2, 30L1, and 30L2.

  (Developer seal member and developer seal opening device)

  The developer seal member and developer seal opening device according to this embodiment will be described with reference to FIGS. FIG. 9 is an exploded perspective view of the cartridge B according to the present embodiment. 10 and 11 are diagrams illustrating a state in which the developer seal member of this embodiment is wound up.

  The toner container 14 has an opening 14 a (see FIGS. 1 and 2) provided for supplying toner to the developing roller 10. As shown in FIG. 9, a developer seal member (hereinafter referred to as toner seal) 50 for shielding the toner and the developing roller 10 is welded around the opening 14a.

  As shown in FIG. 10A, the toner seal 50 includes a substantially rectangular seal pattern (hereinafter referred to as a heat welding portion) 50a, which is a joint provided in the toner storage container 14 so as to surround the opening 14a. It is joined (welded) to the periphery of the opening 14a by 50b, 50c and 50d.

  The toner seal 50 has a portion welded to the toner storage container 14 and a portion not welded (free end). In addition, the toner seal 50 includes a folded portion 50f between a portion welded to the toner storage container 14 and a portion not welded. Then, the toner seal 50 is folded at the folding portion 50f.

The tip 50g of the portion that is not welded is fixed to the developer seal take-up shaft 51 by means such as welding or adhesion.

  The developer seal opening device C is configured to wind up and open the toner seal 50 from the opening 14 a sealed by the toner seal 50. And it has a developer seal winding shaft 51 and a gear portion 51a. When the driving force is transmitted to the gear portion 51a of the winding shaft 51 by driving force transmitting means described later, the winding shaft 51 rotates in the arrow G1 direction as shown in FIG. As a result, the take-up shaft 51 starts to take up the toner seal 50.

  Specifically, when the leading end 50g is wound around the winding shaft 51, a winding force is applied to the folded portion 50f, and the toner seal 50 is first peeled off from the substantially rectangular heat welding portion 50b (FIG. 10). (See (b)).

  At that time, when the width W1 of the heat welded portion 50b in the direction intersecting (substantially orthogonal) with respect to the pulling direction X of the toner seal 50 is the maximum width, pulling that occurs when the toner seal 50 is peeled off is generated. The force peaks. That is, the load torque applied to the winding shaft 51 reaches a peak.

  Next, as the toner seal 50 is wound around the developer seal winding shaft 51, the toner seal 50 is peeled off from the upper and lower heat welding portions 50a and 50c (see FIG. 11A).

  Further, the toner seal 50 is wound around the developer seal winding shaft 51. As a result, the folded portion 50f is peeled off while moving the thermal welding portion 50d (see FIG. 11B).

  In the present embodiment, the width and the angle θ of the heat welding parts 50b and 50d are set to be the same. Accordingly, the load torque applied to the developer seal take-up shaft 51 is the same when the toner seal 50 is peeled off from the heat welded portion 50b and the heat welded portion 50d.

  Therefore, the force when the folded portion 50f of the toner seal 50 is peeled off from the heat welding portions 50b and 50d is maximized. Therefore, the load torque applied to the winding shaft 51 is also maximized.

  In this embodiment, the developer seal member is thermally welded to the developer storage container by the seal pattern of the welding horn. However, the developer seal member may be bonded to the developer storage container by a bonding portion such as a double-sided tape or an adhesive.

  (Stirring member)

  The stirring member according to the present embodiment will be described with reference to FIGS. 12, 13, and 14. FIG. FIG. 12 is an exploded perspective view for explaining the configuration of the stirring member. FIG. 13 is an exploded perspective view for explaining the configuration of the drive transmission unit of the stirring member. FIG. 14 is a perspective view for explaining the movement of the drive transmission unit of the stirring member.

  First, the stirring member 55 far from the opening 14a of the toner container 14 will be described. One end of the stirring member 55 in the longitudinal direction is pivotally supported by the coupling member 56 from the outside of the toner container 14 through the shaft hole 14c.

Here, the coupling of the stirring member 55 and the coupling member 56 is such that the two-way chamfer 55a provided at one end of the stirring member 55 in the longitudinal direction and the two-way chamfering shaft 56a of the coupling member 56 are fitted. This is done by the retaining tab 56b of the coupling member 56 being caught in the fixing hole 55b of the stirring member 55. A seal member 57 is provided between the coupling member 56 and the shaft hole 14c. The seal member 57 prevents toner from leaking from the shaft hole 14 c of the toner storage container 14.

  On the other hand, an end shaft 55c is provided at the other end of the stirring member 55 in the longitudinal direction. The stirring member 55 is pivotally supported by inserting the end shaft 55c into the hole 14d.

  An agitation drive gear 58 supported by a side cover (not shown) is provided on the outer side of the coupling member 56 in the longitudinal direction (the rotation axis direction of the agitation member). The agitation drive gear 58 transmits the driving force transmitted from the driving force transmission means having a gear train described later to the coupling member 56.

  The elastic sheet member 60 made of PPS (polyphenylene sulfide) is fixed to the stirring member 55 by means such as screwing, adhesion, welding, or heat caulking.

  Next, the stirring member 55 closer to the opening 14a of the toner container 14 will be described. One end of the stirring member 55 in the longitudinal direction is pivotally supported by the first driving force transmission member 70 from the outside of the toner container 14 through the shaft hole 14c.

  Here, the stirring member 55 and the first driving force transmission member 70 are coupled to each other by a two-sided chamfering hole 55 a provided at one end in the longitudinal direction of the stirring member 55 and a two-sided shaft 70 a of the transmission member 70. The engagement is further performed by hooking the retaining claw 70b of the transmission member 70 into the fixing hole 55b of the stirring member 55. A seal member 57 is provided between the transmission member 70 and the shaft hole 14c. The seal member 57 prevents toner from leaking from the shaft hole 14 c of the toner storage container 14.

  On the other hand, an end shaft 55c is provided at the other end of the stirring member 55 in the longitudinal direction. The stirring member 55 is pivotally supported by inserting the end shaft 55c into the hole 14d.

  The transmission member 70 has a threaded portion 70c. The screw portion 70 c meshes with the screw portion 71 a provided on the second driving force transmission member 71. Further, an agitation drive gear 59 supported by a side cover (not shown) is provided outside the transmission member 70 in the longitudinal direction (in the direction of the rotation axis of the agitation member). When the cartridge B is mounted on the image forming apparatus main body A for the first time, the screw portion 71a can rotate with respect to the screw portion 70c (tightened state).

  The agitation drive gear 59 transmits the driving force transmitted from the driving force transmission means having a gear train, which will be described later, to the transmission member 71, the transmission member 70, and the agitation member 55.

  A mechanism for transmitting a driving force from the driving force transmitting means to the stirring member will be described with reference to FIG. The agitation drive gear 59 has a protrusion 59a that transmits driving force, and the transmission member 71 has a rib 71b that transmits driving force. The agitation drive gear 59 and the transmission member 71 are provided substantially coaxially. When the agitation drive gear 59 rotates in the arrow G2 direction (FIG. 13), the transmission surface of the protrusion 59a comes into contact with the drive transmission rib 71b of the transmission member 71. Thereby, the driving force for rotating the transmission member 71 is transmitted.

  Next, the movement of the transmission member 70 and the transmission member 71 will be described with reference to FIG.

  As shown in FIG. 14A, the flange portion 71c of the transmission member 71 and the flange portion 70d of the transmission member 70 face each other with a gap.

  As shown in FIG. 14B, the driving force that rotates in the direction of the arrow G <b> 2 from the stirring drive gear 59 is transmitted to the transmission member 71. As a result, the screw portion 71a rotates in the tightening direction of the screw portion 70c (see FIG. 13). At this time, the stirring member 55 and the elastic sheet member 60 connected to the transmission member 70 are not rotated because the toner in the toner storage container 14 has a resistance (load).

  As shown in FIG. 14C, the screw portion 71 a is fastened to the screw portion 70 c by the rotation of the transmission member 71. Thus, the drive is transmitted to the rib 71b of the transmission member 71 while the transmission surface of the protrusion 59a slides in the direction of the arrow G3.

  As shown in FIG. 14D, when the flange portion 71c and the flange portion 70d abut against each other, the driving force that rotates in the direction of the arrow G2 is transmitted to the transmission member 70.

  As described above, by providing the transmission member 71, a time difference can be provided from when the driving force is transmitted to the stirring drive gear 59 from the driving source such as the motor 23 to when the driving force is transmitted to the transmission member 70. .

  Further, the length of the gap between the flange portion 71c and the flange portion 70d or the pitch of the screw portions 71a and 70c is changed. Thereby, the time from when the driving force is transmitted from the driving source such as a motor to the driving agitation gear 59 until the driving is transmitted to the transmission member 70 can be adjusted.

  In this embodiment, the transmission member 70 and the transmission member 71 are provided in the drive transmission portion of the stirring member 55 closer to the opening 14 a of the toner storage container 14. However, you may provide in the drive transmission part of the stirring member 55 far from the opening 14a.

  In FIG. 2, the agitating members 55 closer to and farther from the opening 14 a rotate in a direction to supply toner to the developing roller 10. When the respective rotational angular speeds are ωa and ωb, the rotational angular speed ωa of the stirring member 55 close to the opening 14a is set fast so that ωa> ωb is satisfied. This facilitates the supply of toner to the developing roller 10. Conversely, the rotational angular speed ωb of the distant stirring member 55 is set to be slow as long as toner can be supplied in the vicinity of the stirring member 55 near the opening 14a. Accordingly, it is possible to prevent the toner from being deteriorated due to excessive stirring by the stirring member 55 at a position far from the developing roller 10.

  (Transmission of drive force from drive source and drive force transmission means)

  Transmission of driving force from the driving source according to the present embodiment to the stirring member and the developer seal opening device will be described with reference to FIGS. 15, 16, and 17. FIG. FIG. 15 is a perspective view for explaining transmission of driving force to the stirring member. FIG. 16 is a perspective view for explaining transmission of driving force to the developer seal member winding shaft of the developer seal opening device.

  The image forming apparatus main body A includes a driving force transmission member 80 (see FIG. 5) having a substantially triangular twisted hole. A triangular coupling 81 a that is a protrusion formed at the tip of the drum gear 81 is attached to one end of the photosensitive drum 7 in the longitudinal direction (the rotational axis direction of the photosensitive drum 7).

When the cartridge B is attached to the apparatus main body A, the drive is transmitted to the cartridge B from a drive source such as the motor 23 included in the apparatus main body A. Therefore, the driving force transmission member 80 and the triangular coupling 81a are fitted to transmit the drive. The driving force is transmitted by meshing the helical gear 81b of the drum gear 81 with the developing roller gear 82 (first gear) provided at one end in the longitudinal direction of the developing roller 10, and further, the idler gear 83. , 84 and transmitted to the stirring drive gear 59. Further, the speed is reduced by the idler gear 85 and the drive is transmitted to the stirring drive gear 58. As shown in FIG. 15, the photosensitive drum 7 rotates in the arrow G4 direction, and the developing roller 10 rotates in the arrow G5 direction.

On the other hand, as shown in FIG. 16, the driving force transmitted from the driving source of the apparatus main body A is a gear 86 provided at the other end of the developing roller 10 in the longitudinal direction (rotating axis direction) . gear)
Then, the speed is reduced by idler gears 87, 88, and 89, and the drive is transmitted to the gear portion 51 a of the developer seal winding shaft 51. As a result, the developer seal take-up shaft 51 rotates.

  Next, the operation of the stirring member and the developer seal take-up device when the operator mounts a new cartridge B in the apparatus main body A will be described with reference to FIGS.

  First, the driving force transmitting member 80 and the triangular coupling 81a are fitted, and the driving force is transmitted from the driving source to the triangular coupling 81a.

  Next, the driving force is transmitted to the developer seal winding shaft 51 by the driving force transmitting means provided in the cartridge B described above. Then, the take-up shaft 51 rotates in the direction of the arrow G1, and the toner seal 50 starts to be taken up.

  Simultaneously with the winding operation of the toner seal 50, the agitation drive gear 59 is rotated in the direction of the arrow G2 by the driving force transmitting means described above. Then, the screw part 71a rotates in the tightening direction of the screw part 70c. At this time, the stirring member 55 and the elastic sheet member 60 connected to the transmission member 70 are not rotated because the toner in the toner storage container 14 has a resistance (load). Further, since the driving force is not transmitted to the transmission member 70, the stirring member 55 remains stopped.

  Thereafter, when the flange portion 71c and the flange portion 70d come into contact with each other, the driving force that rotates in the direction of the arrow G2 is transmitted to the transmission member 70, and the stirring member 55 starts to rotate. Accordingly, since the stirring member 55 starts to rotate after a predetermined time has elapsed after the toner seal 50 starts to be wound, the timing at which the stirring member 55 starts to rotate can be delayed.

  The predetermined time is from when the toner seal 50 starts to be separated from the joining portion (for example, the seal patterns 50a, 50b, 50c, and 50d) until the folded portion 50f passes through a portion of the joining portion that intersects the extraction direction X. This time is preferred.

  In this way, the stirring member 55 starts to rotate later than the timing at which the pulling force generated when the toner seal 50 is peeled off reaches a peak. Therefore, the maximum load torque obtained by adding the load torque applied to the take-up shaft 51 and the load torque applied to the stirring member 55 when the toner seal 50 is taken up is reduced. Accordingly, the driving torque for driving the take-up shaft 51 and the stirring member 55 can be reduced, which contributes to downsizing and cost reduction of the driving source such as the motor 23.

  In this embodiment, the driving force transmitting member 80 and the triangular coupling 81a are fitted to transmit the driving force. However, the developing roller gear 82 at the end of the developing roller 10 may be provided with a triangular coupling portion and engaged with the driving force transmitting member 80 to receive the driving force from the apparatus main body A.

In the present embodiment, a series of gear trains such as a helical gear 81b, a developing roller gear 82, idler gears 83, 84, 85, agitation drive gears 58, 59, and the like, a transmission member 70, and a transmission member 71 are driven. It is used as a transmission means. Of course, the driving force transmission means according to the present embodiment is not limited to this. For example, various driving force transmission means can be employed by appropriately selecting and combining pulleys, belts, and the like.

  Next, the effect of reducing the load torque of the entire cartridge B (developing device 19) by shifting the timing at which the toner seal 50 starts to be wound and the timing at which the stirring member 55 starts to rotate will be described with reference to FIG. . The horizontal axis in FIG. 17 indicates time, and the vertical axis indicates the load torque of the process cartridge.

  FIG. 17B shows a torque fluctuation value when the winding operation of the toner seal 50 and the rotation of the stirring member 55 are simultaneously activated. Times (T1) and (T2) on the time axis are when the width of the heat-welded portion 50b in the direction intersecting (substantially orthogonal to) the drawing direction X (FIG. 10) of the toner seal 50 is the maximum width. Indicates. Therefore, the load torque applied to the winding shaft 51 of the toner seal 50 at this time increases.

  At time (T1), the opening 14a is closed by the toner seal 50. Therefore, when the stirring member 55 rotates in this state, the load torque applied to the stirring member becomes the highest.

  At time (T2), the toner seal 50 is wound around the winding shaft 51, whereby a part of the opening 14a is opened. Accordingly, when the stirring member 55 rotates, toner is supplied to the developing chamber 13a. Therefore, the load torque applied to the stirring member 55 is reduced.

  At time (T3), since the opening 14a is completely opened, the load torque applied to the stirring member 55 is the lowest.

  At time (T4), the winding of the toner seal 50 is completed.

  The time (T1) shown in FIG. 17B is the state shown in FIG. 10B, the time (T2) is the state shown in FIG. 11A, and the time (T3) is the state shown in FIG. This is the state shown.

  Next, the configuration of the present embodiment will be described with reference to FIG.

  First, the time (T1) shows the time when the width of the heat welded portion 50b reaches the maximum width in the direction intersecting (substantially orthogonal to) the drawing direction X (FIG. 10) of the toner seal 50. Therefore, the load torque applied to the winding shaft of the toner seal 50 at this time increases. However, the stirring member 55 is stopped at time (T1). Therefore, the load torque of the entire cartridge B due to the rotating member such as the stirring member and the winding shaft is reduced.

  At time (T 2), the toner seal 50 starts to be wound around the winding shaft 51. Further, at time (T2), a part of the opening 14a is already open. Accordingly, when the stirring member 55 rotates, toner is supplied to the developing chamber 13a. Therefore, the load torque applied to the stirring member 55 is lower than in the state where the opening 14a is closed.

  At time (T3), since the opening 14a is completely opened, the load torque applied to the stirring member 55 is the lowest.

17 (b) and 17 (c), when the stirring member 55 starts rotating after a lapse of a predetermined time after the toner seal 50 starts to be wound up, it is generated by a plurality of rotating members as shown in FIG. 17 (c). The maximum value of the entire load torque can be reduced. Therefore, the drive torque for driving the winding shaft 51 and the stirring member 55 can be reduced. Therefore, it is possible to contribute to downsizing and cost reduction of the drive source such as the motor 23. Further, by reducing the load torque applied to the rotating member, it is possible to contribute to reducing the size and cost of the rotating member.

  A stirring member according to Embodiment 2 will be described with reference to FIGS. FIG. 18 is an exploded perspective view for explaining the configuration of the drive transmission unit of the stirring member according to the second embodiment. FIG. 19 is a cross-sectional view for explaining the configuration of the drive transmission unit of the stirring member according to the second embodiment. Note that the description of the same configuration as that of the first embodiment is omitted.

  The driving force transmission member 90 has a two-way shaft 90a at one end thereof. The two-way taking shaft 90 a is fitted into the two-way taking hole 55 a of the stirring member 55. Further, the retaining claw 90 b of the transmission member 90 is caught in the fixing hole 55 b of the stirring member 55. Thereby, the transmission member 90 and the stirring member 55 are engaged.

  A hole 90c is provided at the other end of the transmission member 90, and a friction member 91 made of rubber or fiber material is attached to the bottom of the hole 90c.

  In addition, the agitation drive gear 95 has a hole portion 95b that engages with the support shaft 94a of the side cover 94 and a gear portion 95c at one end. The other end portion of the gear 95 has a shaft portion 95a to which a friction member 92 made of rubber or fiber material is attached.

  A pressing member 93 made of a spring or the like is fitted on the shaft on the outer periphery of the hole portion 95b, and is sandwiched between the side cover 94 and the gear portion 95c. Thereby, an appropriate pressure is applied to the friction member 92 attached to the tip of the shaft portion 95a and the friction member 91 attached to the hole portion 90c, and a desired friction force can be set.

  Next, a configuration for delaying the timing at which the stirring member 55 starts to rotate from the timing at which the toner seal 50 starts to be wound will be described.

  In the state where the opening 14 a is closed by the toner seal 50, the toner is applied to the stirring member 55 and the elastic sheet member 60. Therefore, even if the stirring drive gear 59 receives a driving force transmitted by a gear train (not shown), a slip occurs between the connecting portions of the friction member 92 and the friction member 91. Therefore, the stirring member 55 remains stopped.

  When the toner seal 50 starts to be wound around the winding shaft 51 and the stirring member 55 rotates with a part of the opening 14a opened, toner is supplied to the developing chamber 13a. Therefore, the load torque applied to the stirring member 55 is lower than in the state where the opening 14a is closed. Further, when the winding of the toner seal 50 is completed, the opening 14a is completely opened, so that the load torque applied to the stirring member 55 is further reduced.

  Therefore, the predetermined time is set to a time after the winding shaft 51 starts to open the opening 14a. As a result, it is possible to employ a drive source that is smaller in size or low in cost. In addition, since the load torque is reduced, it is possible to employ lower cost parts for the stirring member and the gear.

If the frictional force generated at the connecting portion between the friction member 92 and the friction member 91 is set equal to the torque required to rotate the stirring member 55 when the opening 14a is fully opened, the cartridge B (developing device 19) It is possible to reduce the maximum value of the entire load torque generated by the plurality of rotating members included in the. Therefore, it can contribute to size reduction and cost reduction of a drive source such as a motor. In addition, by reducing the load torque applied to the rotating member, the rotating member can be downsized,
It can also contribute to cost reduction.

It is a schematic sectional drawing which shows the structure of the electrophotographic image forming apparatus which concerns on a present Example. It is a schematic sectional drawing of the process cartridge which concerns on a present Example. FIG. 2 is a perspective view illustrating a state where a process cartridge is mounted on the image forming apparatus main body according to the present exemplary embodiment. FIG. 3 is a perspective view illustrating a mounting unit of the image forming apparatus main body according to the present exemplary embodiment. FIG. 3 is a perspective view illustrating a mounting unit of the image forming apparatus main body according to the present exemplary embodiment. 1 is an external perspective view of a process cartridge according to an embodiment. 1 is an external perspective view of a process cartridge according to an embodiment. It is a disassembled perspective view of the process cartridge which concerns on a present Example. It is a disassembled perspective view of the process cartridge which concerns on a present Example. It is a figure explaining the state by which the developer seal member of a present Example is wound up. It is a figure explaining the state by which the developer seal member of a present Example is wound up. It is a disassembled perspective view for demonstrating the structure of the stirring member which concerns on a present Example. It is a disassembled perspective view for demonstrating the drive transmission part structure of the stirring member which concerns on a present Example. It is a perspective view for demonstrating the motion of the drive transmission part which concerns on a present Example. It is a perspective view for demonstrating transmission of the driving force to a stirring member. It is a perspective view for demonstrating transmission of the driving force to the developer seal member winding shaft which a developer seal opening device has. It is a figure which shows the torque of a present Example. FIG. 6 is an exploded perspective view for explaining a drive transmission unit configuration of a stirring member according to a second embodiment. FIG. 9 is a cross-sectional view for explaining a drive transmission unit configuration of a stirring member according to a second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical means 2 Recording medium 3 Conveyance means 4 Transfer roller 5 Fixing means 6 Discharge tray 7 Electrophotographic photosensitive drum 8 Charging roller 9 Cartridge door 10 Developing roller 11 Magnet roller 12 Developing blade 13 Developing frame body 14 Developer storage container (toner Storage container)
14a Opening 17 Cleaning means 18 Drum frame 19 Developing device 20 Photosensitive unit 23 Motor (drive source)
24 gear 31 coupling member 50 toner seal (developer seal member)
50a, 50b, 50c, 50d Seal pattern 50f Folding part 50g Tip part 51 Developer seal winding shaft 51a Gear part 55 Stirring member 55a Two-way taking hole 55b Fixed hole 55c End shaft 56 Coupling member 57 Sealing member 58, 59 Stirring Drive gear 59a Drive transmission protrusion 60 Elastic sheet member 70 First drive force transmission member 70a Two-way shaft 70b Retaining claw 70c Screw part 70d Flange part 71 Second drive force transmission member 71a Screw part 71b Drive transmission rib 71c Flange Portion 80 Driving force transmission member 81 Drum gear 81a Triangular coupling 81b Helical gear 82 Developing roller gear 83, 84, 85, 87, 88, 89 Idler gear 90 Driving force transmission member 90a Two-sided shaft 90b Retaining claw 90c Hole 91 , 92 Friction member 93 Press member 94 Side cover 95 Stirring drive gear 95a Shaft portion 95b Hole portion 95c Gear portion A Electrophotographic image forming apparatus B Process cartridge C Developer seal opening device

Claims (8)

A developing device detachable from the electrophotographic image forming apparatus main body,
A developing roller that develops the electrostatic latent image formed on the electrophotographic photosensitive drum with a developer, and that is rotated by a driving force from a motor provided in the apparatus main body. A developing roller having a first gear provided at the end and a second gear provided at the other end in the longitudinal direction;
A developer storage container for storing the developer;
A stirring member provided in the developer storage container, the stirring member stirring the developer and supplying the developer to the developing roller;
An opening provided in the developer container for supplying the developer to the developing roller;
A developer seal member for sealing the opening;
A developer seal unsealing device having a take-up shaft for winding the developer seal member to open the developer seal member, to which a driving force is transmitted via the second gear;
A driving force transmission mechanism that transmits a driving force to the stirring member via the first gear, the first driving having a first screw portion that transmits the driving force from the first gear. A force transmission member, and a second driving force transmission member connected to the stirring member, the second driving force transmission member having a second screw portion meshed with the first screw portion, and the first driving force transmission member After the driving force is transmitted and the first screw part is rotated by a predetermined amount and fastened to the second screw, the second driving force transmitting member rotates to switch the rotation direction of the motor. And a driving force transmission mechanism that transmits a driving force to the stirring member after a predetermined time has elapsed since the winding shaft began to rotate,
A developing device comprising: The driving force transmission mechanism is
When the first screw portion is fastened to the second screw portion, a first flange portion included in the first driving force transmission member and a second flange included in the second driving force transmission member. The developing device according to claim 1, wherein the second driving force transmission member rotates when the flange portion abuts. The developer seal member is
It is joined to a joint provided so as to surround the opening on the upstream side in the drawing direction of the developer seal member from the winding shaft,
3. The developing device according to claim 1, wherein the driving force transmission mechanism transmits the driving force to the stirring member after a predetermined time has elapsed since the developer seal member started to be separated from the joint portion. .   4. The developing device according to claim 1, wherein the developer seal member has a folded end portion on a side opposite to the winding shaft across the opening. 5.   5. The developing device according to claim 1, wherein the predetermined time is set to a time after the developer seal opening device starts to open the opening.   The predetermined time is a time from when the developer seal member starts to be separated from the joint portion to when the folded end portion passes through a portion of the joint portion that intersects the drawing direction. The developing device according to claim 3. In a process cartridge that can be attached to and detached from the electrophotographic image forming apparatus main body,
A developing device according to any one of claims 1 to 6;
An electrophotographic photosensitive drum;
A process cartridge comprising: In an electrophotographic image forming apparatus for forming an image on a recording medium,
(I) the process cartridge according to claim 7;
(Ii) transfer means for transferring a developer image formed on the electrophotographic photosensitive drum of the process cartridge to the recording medium;
(Iii) transport means for transporting the recording medium;
An electrophotographic image forming apparatus comprising:

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